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April 24, 2013

Contraceptives were the subject of the Federal
Circuit's recent decision in Bayer
Healthcare Pharmaceuticals, Inc. v. Watson Pharmaceuticals, Inc. But, unfortunately,
it's a rather fact-specific case with nothing of prurient or even much general
legal interest to spice up the lonely patent practioner's day.

The battle was over Bayer's RE37,564 patent and,
specifically, claims 13 and 15:

13. A
combination product for oral contraception, comprising (a) 23
or 24 daily dosage units, each containing 0.020 mg of ethinylestradiol, and 2.5
to 3.0 mg of drospirenone, and (b) 5 or
4, respectively, active ingredient-free placebo pills or other indications to
show that the daily administration of the 23 or 24 dosage units, respectively,
is to be followed by 5 or 4, respectively, pill-free or placebo pill days, wherein
each of the dosage units containing drospirenone contains the same amount of
drospirenone.

15. A
combination preparation of claim 13, which comprises 24 dosage units and 4
placebo pills or other indications to show that no dosage unit or placebo pill
is administered during the last 4 days of the menstrual cycle.

A purpose of the claimed
invention was to provide an alternative to the standard 21/7 dosing regime of
combined oral contraceptives ("COC"), which combined a synthetic
progestin (e.g., drospirenone (DRSP))
and estrogen (e.g., ethinylestradiol,
("EE")). In the 21/7 dosing regime, a woman takes a single, synthetic
hormone-containing pill for 21 days followed by a period of 7 days of a placebo
(i.e., a pill containing no hormone),
also called "the pill-free interval." The 21/7 regime is thought to
mimick the normal menstrual cycle while providing a regular break from the
exposure to the synthetic hormone, thereby, mitigating potential side effects.

To further reduce side effects, Bayer sought to
reduce the daily dosage of the drugs. In particular, they reduced the daily
dose of EE from 150 µg/pill to 20 µg/pill. But with the lower dose, some
ovarian activity and follicular maturation can persist, and any intake errors (i.e., missed pills) could result in "escape"
ovulation and unintended pregnancy. To address this issue, Bayer increased the
number of days on the hormone-containing pill and decreased the pill-free
interval, coming up with the claims' 23/5 and 24/4 regimes and demonstrating
that shortening the pill-free interval to four or five days (from seven) improved
contraceptive efficacy. Bayer was awarded a patent, which ultimately reissued
as the '564 patent.

So, everybody was happy, at least until Watson
Pharmaceuticals came along and sought to upset the apple cart. Watson filed an
ANDA and asserted that Bayer's patent was invalid as obvious. Bayer took issue with
this and litigation ensued as Bayer sued Watson for infringement under 35 USC §
271(e)(2) for the filing of the ANDA.

In the District Court both sides filed for summary
judgment on the obviousness issue, Watson asserting that the claims of the '564
patent were obvious over numerous publications and Bayer responding nuh-uh
(but, presumably, in a more elaborate and eloquent manner). The District Court
found Bayer's argument persuasive and held against Watson. Watson, naturally,
appealed.

Watson argued that that patent was obvious over
Australian patent application 55094/90 ("AU'094") in view of any one
of several other publications. AU'094 disclosed COCs containing 20-40 µg EE and
1-10 mg DRSP per pill, which encompass the amounts in the '594 claims on
appeal. Watson further argued that the secondary publications each taught the
23/5 and/or 24/4 dosing regimes and suggested them as useful for shortening the
pill-free interval and addressing the missed-pill problem, thus providing the
motivation to combine such regimes with the AU'094 COCs.

Bayer disagreed. They argued that AU'094 and at
least one of the other secondary references were directed to narrow
subpopulations of patients primarily in need of hormone–replacement therapy
and, therefore, the ordinary artisan would not have combined those references
when seeking to make a COC. Bayer also argued that in view of the entrenched
21/7 regime and the perceived risks of increasing the days on hormone, the art
as a whole taught away from the claimed COC.

The Federal Circuit agreed with Watson, holding
that all the limitations of the claims were present in the prior art along with
an express motivation to combine them. AU'094 disclosed COCs encompassing those
of the asserted claims. A second publication, EP 0253607 ("EP'607")
disclosed COCs with 8-30 µg/dose EE and suitable progestins (but not DRSP) as
well as the asserted claims' 24/4 and 23/5 dosage regimes. The Federal Circuit
also noted that the prior art recognized the escape ovulation problem that
could result through inadvertent extension of the pill-free interval with one
or two missed pills. And the Court pointed to Bayer's own expert, who
acknowledged a greater risk of "missed pill" ovulation with low dose
COCs. As the prior art recognized the problem and suggested the claimed
solution, the Court held that the claims were obvious.

Bayer countered with several arguments that the
Federal Circuit swatted away like so many flies. To Bayer's assertion that AU'094
and EP'607 were primarily directed to hormone replacement therapy, the Court
responded that they plainly disclosed contraceptive applications as well. To
Bayer's assertion that conventional wisdom suggested the 21/7 dosing regime,
the Court responded that this does not overcome the express teachings of the
several applied publications to shorten the pill-free interval. To Bayer's
assertion that Goldstuck prior art taught decreasing the pill-free interval
while concurrently increasing the hormone dose for at-risk patients, the
Federal Circuit replied that these two measures were never linked as mutually
dependent, each being expected to reduce missed-pill ovulation risk independent
of the other.

The Federal Circuit similarly addressed in short
order Bayer's evidence of secondary indicia of non-obviousness. To Bayer's
assertion of unexpected results of reducing follicular activity with the 25/3
and 24/4 regimes compared to the 21/7 regime, the Federal Circuit responded
that that was just what would have been expected by administering additional
active pills, a matter of "common sense," as even Bayer's expert
agreed. To Bayer's assertion that the FDA requested clinical safety and
efficacy data to justify additional hormone exposure, the Federal Circuit
merely responded that that the FDA was doing nothing more its job, i.e., requiring safety and efficacy
data. To Bayer's assertion that the invention "was widely praised by
experts in the COC field," the Federal Circuit responded that several
journal citations merely referred to Bayer's published results or discussed
possible non-contraceptive indications for 24/4 COC regimens and, furthermore,
the first-named author on an article praising the Bayer 24/4 COC regime as an "innovative
strategy" happened to be the first-named inventor on the '564 patent. And,
finally, in response to Bayer's contention that the defendant's copying of the
claimed COC preparations was evidence of non-obviousness, the Federal Circuit
replied that the defendants had to copy the claimed preparations to demonstrate
bioequivalence, as required for FDA approval.